The invention concerns an espresso brewing device according to the generic term of claim 1.
Such an already-known espresso brewing device consists of a brewing unit, a rotatable magazinexe2x80x94also rotatable via an electric motorxe2x80x94with a magazine table whereupon several magazine tubes also termed cartouches for holding single-serving capsules containing coffee powder are arranged approximately in the circumferential direction of the magazine table (EP 1 460 366 A1). In order to feed the single-serving capsules individually into the brewing unit, a comparatively complicated lever mechanism coupled with an electronic magnet is provided. The lever mechanism acts upon swivel-mounted latches both of whose sides are provided with a supporting surface each for supporting an individual serving of coffee. The latches take hold of a projecting edge of the individual coffee servings that are stacked inside the magazine tubes with their edges and thus their bases facing upwards. When the lever mechanism is operated, the respective lowest single-serving capsule separates from the latches and drops into that part of the brewing chamber that was swivelled into position below the capsule, whereby the brewing chamber is an integral part of the brewing unit. In order to brew the coffee, the above-mentioned lower part of the brewing chamber must be swivelled to the upper part of the brewing chamber whose upper surface is equipped with a piston-shaped stopper with pyramid-like projections and openings. Subsequently a ram is raised from the lower surface of the lower part of the brewing chamber, entering the single-serving capsule in order to introduce hot water for brewing into the individual coffee serving. After breaking the top-side base of the individual coffee serving by means of the pyramid-shaped projections, the brewed coffee or espresso is able to flow out through the upper openings of the stopper. Subsequently the brewing chamber is conveyed back to its original position and the now empty single-serving capsule is ejected from the brewing chamber via the stopper that continues to rise. The swivel mechanism and operational mechanism of the brewing chamber and of the stopper able to move therein are relatively complicated. It is not clear just how the empty single-serving capsule is to be ejected completely, since a magazine tube is positioned right above when the brewing chamber is in its original position.xe2x80x94For the selection of a coffee type or rather a single-serving capsule containing the desired coffee type, each magazine tube is provided with a window permitting the consumer to visually recognize which coffee type is contained in the respective magazine tube, as well as recognize which coffee type is located above the brewing unit at this point and will be used next for brewing a cup of coffee. A colour identification, for example, is suggested as a means of recognizing the desired coffee type. However, it is also possible to provide each single-serving capsule with a code able to be registered electronically via a suitable reading device in order to recognize single-serving capsules and particularly their contents. This recognition is utilized, for example, to show via a display which type of coffee is being used to brew the next cup of coffee. A further variation includes a control panel for the selection of the desired coffee type whereby the magazine table is rotated by means of an electric motor until the respective magazine tube containing the selected coffee type is in the effective position above the brewing unit. The means for achieving this are not shown. Recognition of a code applied on the circumference of a single-serving capsule whereby the code could be scanned through a window appears difficult, if not impossible, while the recognition of a code on the base of the single-serving capsule, for example, is out of the question since the base is covered by the single-serving capsule stacked above it.
Another state-of-technology drink dispensing machine for drinks such as coffee or tea is provided with a magazine table carrying a number of magazine tubes arranged along its circumference and holding single-serving capsules (EP 1 002 490 A1). The magazine table can be rotated via a drive sysstem, also a Maltese-cross-type drive ssystem, in such a way that one magazine tube holding the desired single-serving capsules can be positioned adjacent to a water/steam supplying device. From this position the bottom capsule of the single-serving capsules stacked with their edge facing downwards can be pushed via a thrusting device into the position below the water/steam supplying device. The thrusting device used for this purpose is located entirely within the configuration of the magazine tubes centrally above the magazine table. Although this machine is not very high, the water/steam supplying device must be located closely adjacent to the configuration of the magazine tubes due to the arrangement of the thrusting device.
For the horizontal conveyance of single-serving capsules to be selected from a magazine with its magazine chambers arranged in a linear manner next to each other and to be conveyed into a brewing unit positioned adjacent to the magazine at a certain distance from it, the use of a conveyor band is already known, whereby the conveyor band is essentially located below the magazine chambers and is equipped with a delivery station for the horizontal delivery of a selected single-serving capsule from the conveyor band to the brewing unit (U.S. Pat. No. 3,812,273). The linear configuration of the magazine chambers, however, requires a correspondingly large extension of the entire assembly with regard to its breadth. In addition, conveyance and delivery of the selected single-serving capsule from the magazine to the brewing unit necessitate expensive technology.
In the case of another device for the brewing of beverages, a rotatable drum with an intake opening for a selected single-serving capsule is positioned below pipe-shaped magazine compartments wherein single-serving capsules are stacked with their base facing downwards (FR-A 1 564 088). The selected single-serving capsule is conveyed via the drum to an opening within a stationary plate bar through which the single-serving capsule is conveyed to another conveying device for its horizontal conveyance up to a beverage preparation unit, whereby the single-serving capsule is additionally tilted above this unit.xe2x80x94This assembly is complicated, since a selected single-serving capsule must not only be transported horizontally, but must also be released for its sectionally-controlled free drop, and must finally be tilted from its position inside the magazine where its base is facing downwards to the opposite position above the beverage preparation unit where its base is facing upwards.
As far as the coding of the single-serving capsule and control of the espresso brewing device is concerned, single-serving capsules or cartridges for the preparation of foamed beverages provided with at least a code or means of identification whereby the cartridge is identified when the brewing device is being used and whereby the cartridge or its contents are made to undergo the correct operational steps, are already part of the present state-of-technology, including the introduction of a watery medium inside the cartridge (DE 694 00 787 T2). The means of identification may include a bar code printed upon the body of the cartridge and able to be scanned via an optical device. The means of identification may also include one or several strips of a magnetic material able to be read by a magnetic sensor. Preferably, the device for preparing beverages is designed in such a way that the cartridge is processed automatically once it has been inserted into the device.
In general, the use of single-serving capsules provided with means of identification and the identification of those means in order to handle the single-serving unit and its contents correctly, and the introduction of liquid media into the capsule in particular, are revealed in EP 0 455 337 B1.
In the case of another already-known device for the preparation of a beverage using a sachet or single-serving capsule, various single-serving capsules are stored according to contents in different stationary channels that can be opened via one associated actuating button in order to remove a single-serving capsule (EP 0 334 573 B1). The manually-removed single-serving capsule is inserted into an opening below a brewing station in such a way that a micro switch is activated via the single-serving capsule in order to unblock the brewing process. Thus the micro switch serves to identify the correct position of the single-serving capsule before the watery medium is introduced.
It is the task of the present invention to further develop an espresso brewing unit of the generic type mentioned above, without considering its control system at the moment, in such a way that while the low height of the unit is maintained, the access to functionally important parts, particularly to the magazine serving to hold assorted stacks of single-serving capsules, is improved although these parts are positioned securely inside a casing.
This task being the base of the invention is basically implemented according to the characterising part of claim 1.
The magazine table drawer able to be pulled out of the supporting frame of the espresso brewing device supports the magazine table provided with magazine tubes positioned on top and with a pivot pin protruding below for mounting purposes inside the magazine drawer. For the control of its drive, the magazine table may be provided laterally with a zero setting reference mark, whereby a scanner contact or sensor is located in a stationary position on the magazine table drawer in order to scan the above-mentioned reference mark.xe2x80x94An advantage of the magazine table drawer is the fact that the magazine tubes can each be supplied easily from above with single-serving capsules of one particular coffee type. The magazine drawer can then be pushed back into the device wherein the magazine table drawer with its associated elements, especially the magazine tubes holding single-serving capsules, is secure and can be locked, if necessary. In addition, maintenance is simplified due to the fact that the magazine drawer can be pulled out.
In this context it is especially advantageous if the magazine table with the magazine tubes can be separated easily from the magazine table drawer. In this case several fairly basic magazine tables with magazine tubes containing single-serving capsules can be kept ready, so that they cab be interchanged quickly if necessary.
When various coffee types are kept ready for selection, each type must be stored in a different magazine tube in order to be identified. With regard to the further characteristics of the device, in particular the scanning or reading of codes on the magazine capsules via at least one sensor or scanner, the single-serving capsules are placed into the magazine tubes with their base, i.e. their bottom membrane, facing downwards. The brewing unit that is part of the espresso brewing device is further designed in such a way, as characterised below, that a single-serving capsule oriented as described above is able to undergo the brewing process after being conveyed horizontally without turning.
Preferably, according to claim 3 the magazine tubes are each provided, in a lower section of their casing that is raised above the magazine table, with a capsule magazine opening which opens radially outwards with regard to the magazine table. A sliding path for the capsule extends between the magazine table and the brewing unit, whereby one single-serving capsule at a time is able to slide, via a capsule gripper driven by an electric motor, from a magazine tube in the dispensing position up to the brewing unit. In the dispensing position the selected magazine is therefore rotated by the magazine table in such a way that the lowest of the single-serving capsules stacked with their bases facing downwards is conveyed via the capsule gripper through the capsule magazine opening of the magazine tube along the capsule slide path up to the brewing unit.
In order to guide the capsule gripper within the magazine table area when one single-serving capsule is being ejected, the area below each magazine tube is provided, according to claim 4, with a radially-extending capsule ejection slot extending up to the outer edge of the magazine table and open where it meets the edge. When one of the magazine tubes is in the dispensing position, the capsule ejection slot meets a capsule gripping guide formed within the capsule slide path and extending up to the brewing unit. In order to guide the single-serving capsules along the capsule slide path, the latter is provided with additional means in the shape of capsule guides arranges essentially parallel to the capsule gripping guide, whereby the distance between the two capsule guides is somewhat greater than the diameter of the single-serving capsule in the area of its base, i.e. its bottom membrane.
The capsule gripper is part of the capsule conveying device, and for the purpose of being operated according to claim 5 it is connected via a drive lever and drive mechanism elements with a capsule-conveying driving motor. The drive mechanism elements may include in particular a speed reduction gear located at the capsule-conveying driving motor, and a driving disc connected to the speed reduction gear, whereby the driving stud of the driving disc engages via a driving stud slot with the actuating lever in a sliding manner near one of its ends. The other end of the actuating lever, close to where the lever is mounted on a gripping stud, is provided with a capsule gripping slot wherein the capsule gripper is mounted in such a way that it is also able to slide. The entirety of the drive mechanism converts the rotation movement of the capsule-conveying driving motor into a linear guided movement of the capsule gripper.
When the design of the magazine is low and compact and it is mainly positioned adjacent to the brewing unit, the capsule-conveying device is designed in such a way that the single-serving units are conveyed only horizontally with their base facing downwards. The capsule-conveying device is essentially positioned between the magazine and the brewing unit.
For the actuation of the magazine table, i.e. in order to rotate a selected magazine tube into the dispensing position, the magazine table, according to claim 7, is in an actuation-connection with a Maltese-cross-type drive consisting of a driving motor, a drive mechanism and a Maltese-type disc with a driving stud and positioned below the magazine table on the support frame. Whenever the magazine table is in operation, the driving stud is positioned closely adjacent to one of several Maltese-type gripping flanks located at the lower surface of the magazine table. According to the arrangement of the Maltese-type gripping flanks, each of the magazine tubes positioned above can be shifted step by step into the dispensing position. When the magazine table drawer is pulled out, the Maltese-cross-type drive can be separated from the magazine table via removal of the Maltese-type gripping flank from the driving stud of the Maltese-cross-type drive. This is done easily, since the gripping flanks always assume a definite position according to the dispensing position of the magazine table.
For the purpose of its control, the magazine table should be provided with a zero setting reference mark able to be scanned, whereby this reference mark may be a cam, read mechanically via a controlled contact, or it may be a reference mark designed to be scanned optically or magnetically. The scanner of the zero setting reference mark and a two-direction meter counting all operational steps carried out by the magazine table in each direction of rotation, starting from a zero position of the magazine table, are part of an electronic position recognition device of the magazine table according to claim 9. This device is part of a logical control system controlling a set movement of a randomly selected magazine tube using the shortest possible path in one of the two possible directions of rotation into the dispensing position. The setting time can thus be minimized, whereby apart from a zero position signal or impulse from the zero setting reference mark, only counting impulses according to the steps carried out by the Maltese-cross-type drive are required additionally.
For additional control, or as an alternative to the above-mentioned control system, the magazine table is provided, according to claim 10, with transparent windows so that the base of a single-serving capsule can be scanned, whereby one window is located below each magazine tube. For this purpose at least one sensor/scanner is located below the magazine table at the path of movement of the windows able to rotate together with the magazine plate and directed towards the respective window. The base or a code applied to the base can be scanned through the window and can be converted into a corresponding impulse.
In particular, a sensor according to claim 11 may be located at the dispensing position, whereby the presence of a single-serving unit inside the magazine tube set in the dispensing position can be checked. Thus the possibility that a magazine tube associated with single-serving capsules, especially those containing a particular coffee type, has been set correctly but cannot supply a single-serving capsule to the brewing unit because it is empty can be prevented.
Instead, the magazine can already be checked while entering the dispensing position, not only to find out if there is at least one single-serving capsule in the corresponding dispensing tube, but also if that capsule contains the desired coffee type. This is done according to claim 12. For this purpose a scanner is located in front of the dispensing position in the direction of rotation of the magazine table, whereby a code relating to the coffee type and applied to the base of the lowest-positioned single-serving capsule contained in the selected magazine tube can be read. Thus it can already be determined during the searching part of the operation if the next magazine tube to enter into the dispensing position contains a single-serving capsule with the desired contents. In this case, registration of the respective position of a defined magazine tube via a logical control system can be omitted, since the scanner located in front of the dispensing position is able to convert the entrance of a selected magazine tube into a control signal via a controlling device for the drive of the magazine table, so as to stop the movement of the magazine table in time once the selected magazine tube containing the desired coffee type enters the dispensing position. Only one scanner located in front of the dispensing position is sufficient in this case as long as the drive of the magazine table allows for only one direction of rotation or shifting. However, if two opposite directions of rotation or shifting for the entrance of a randomly-selected magazine tube on the shortest possible path into the dispensing position are possible, then both sides of the dispensing position must be equipped with a scanner each.
Preferably, the magazine and the capsule conveying device interact with a compact brewing unit according to claim 13, whereby the brewing unit includes a spindle piston, actuated via an electric motor and able to be vertically adjusted via rotation. The spindle piston is provided with an inner brewing chamber insert with a downward-projecting piercer for piercing the capsule, whereby the piercer also contains brewing water supply channels. The spindle piston can be lowered via rotation into a brewing position towards a capsule ejector able to swivel and towards a plate with pyramid-shaped projections. A capsule ejection lever engaging with the spindle piston serves to swivel the capsule ejector upwards into an ejection position by raising the spindle piston once the brewing process is finished. Thus the spindle piston is able to assume three positions via rotation, i.e. a receiving position for the single-serving capsule that is pushed horizontally with its base or an outer bulge facing downwards into the space between the spindle piston and the pyramid plate, a brewing position where the brewing chamber is closed by the tight fit of the brewing chamber placed onto the pyramid plate with the capsule ejector, and finally an ejection position where the spindle piston is raised to its highest position, thus operating the capsule ejector.
According to claim 14, this brewing unit with a replaceable pyramid plate and with the capsule ejector on a pyramid support drawer able to be pulled out of the brewing unit may preferably form a basic unit assembly group.
Ejection of the used single-serving capsule occurs automatically when the parallel-guided spindle piston is raised, whereby the capsule ejection lever guided in a sliding manner laterally grips the capsule ejector on one side. This results in the reliable ejection of the single-serving capsule, from the free space between the capsule ejector and the raised brewing chamber insert, from the now open brewing chamber, without any direct manual manipulation of the single-serving capsule.
For the accurate centering of the single-serving capsule prior to the brewing process, the upper surface of the capsule ejector positioned above the pyramid plate is equipped with a capsule centering device able to interact in particular with the outer bulge of the capsule.
The single-serving capsule is guided via its outer bulge in a similar manner along the horizontal capsule slide path between the magazine and the brewing unit, via lateral capsule guides located in succession to the capsule ejector guides, whereby the capsule slide path is part of the brewing unit.